Can A Microwave Overheat? 7 Causes & Fixes

Can a microwave overheat? Like any electronic device, a microwave is susceptible to certain issues when it’s not used properly.

Although microwaves are designed to cope with high temperatures during regular use, certain conditions can lead to overheating.

When the microwave overheats, it not only becomes less efficient, but can also pose safety risks.

In this article I’m going to walk you through the most common causes of an overheating microwave. In each case I’ve also included some essential tips to help you prevent the problem from happening in the first place.

Armed with this knowledge, you’ll be able to confidently use your microwave. Let’s move right onto those possible causes…

#1 Blocked or Restricted Ventilation

All microwaves are equipped with ventilation systems. These are designed to get rid of the excess heat that’s generated when you’re cooking food. 

Problems can occur when these vents become blocked or restricted. Perhaps you cover them accidentally, or they’ve got clogged up with food debris.

When this happens, the microwave’s internal temperature can rise rapidly, leading to overheating. 

To prevent this, ensure the vents on the back or sides of the microwave remain free of obstructions. You should clean it regularly too, as this will clear out any grease or grime that builds up over time.

#2 A Malfunctioning Turntable

The turntable inside your microwave turns so that the heat is spread around efficiently.

If the turntable malfunctions, the microwave may concentrate all of its heat in one area, leading to overheating. 

The solution? Although it’s a bit of a pain, I regularly inspect and clean my turntable. If the turntable won’t turn at all – or it makes an odd noise – it’s time to either replace it or get a professional in.

#3 A Faulty Magnetron

The magnetron is the component that produces the microwaves that heat your food.

If the magnetron becomes faulty or damaged, it may continuously emit microwaves even when the oven is not in use, causing the microwave to overheat. 

If you suspect a malfunctioning magnetron, seek professional repair services to resolve the issue safely. It’s really not a problem I recommend fixing on your own.

#4 Aging Components

No microwave lasts forever and you can expect to replace your appliance every 7-10 years (depending on how hard you work it).

As microwaves age or endure heavy use, some internal components may deteriorate. This leads to increased energy consumption and the potential for overheating.

The trick here is pretty simple. Make sure your microwave isn’t operating beyond its recommended lifespan. Shorten that if the appliance is showing visible signs of wear and tear.

#5 High Operating Temperatures

Using a microwave in an excessively hot environment, such as a kitchen without adequate ventilation or in direct sunlight, can raise the internal temperature beyond safe limits. 

This can cause the microwave to overheat. Try to keep your kitchen well-ventilated and avoid exposing the microwave to direct heat sources too. Relocate it somewhere else in the kitchen if it’s exposed to direct sunlight.

#6 Running It Empty (or Using The Wrong Containers)

Running a microwave empty or with improper containers not suitable for microwave use can lead to overheating. 

Without food or appropriate materials to absorb the microwaves, the microwave’s energy will reflect back into its components, causing overheating. 

Never run your microwave empty, and also ensure you use microwave-safe containers.

#7 Power Surges and Electrical Issues

Power surges or electrical problems can disrupt the microwave’s normal functioning, causing it to overheat. 

To prevent this, plug the microwave into a surge protector and address any electrical issues promptly.

Frequently Asked Questions

Being aware of those seven common causes of an overheating microwave will help you avoid them in the first place!

Here are some quick answers to some other questions that often come up.

What happens if your microwave overheats?

If your microwave overheats, it can lead to reduced efficiency, potential damage to internal components, and in extreme cases, pose safety risks such as electrical fires.

Will a microwave stop working if it overheats?

Typically yes, a microwave can stop working if it overheats. 

In many models, safety mechanisms, such as thermal fuses, are designed to shut off the microwave to prevent further damage or potential hazards. 

Once the microwave cools down, it may start functioning again, but continued overheating can lead to permanent damage. At this point you’ll need to either have it repaired, or replace the microwave altogether.

How do you fix an overheated microwave?

Fixing an overheated microwave typically involves identifying and addressing the underlying cause of the overheating. 

Common solutions may include cleaning and ensuring proper ventilation, repairing or replacing malfunctioning components like the turntable or magnetron, and avoiding misuse such as running the microwave empty or using improper containers. 

However, repairs can be complex and potentially hazardous, so I’d always recommend you get a qualified professional in.


While a microwave can indeed overheat, being aware of the common causes will help you avoid this problem most of the time.

By implementing these tips, you can extend the lifespan of your microwave while enjoying hassle-free cooking!